The present invention generally relates to dairy farm machine milking and to teat cup cleaning related thereto.
Particularly, the invention relates to a method for teat cup cleaning in an automated milking system, and to such an automated milking system.
When a milking animal, such as a cow, presents for milking it is important to ensure that the teat cups to be attached to the teats of the milking animal are clean and free of any condition that could contaminate the teats of the milking animal. This need applies to both manual and automatic application of milking apparatus. Therefore, it is customary to wash the teat cups between the milking of each milking animal, either a cleaning liquid or only water is used.
One such teat cup cleaning technique as used by applicant comprises injecting water from below into the teat cups arranged with their respective teat receiving openings faced towards the floor, whereafter the water is allowed to flush back trough the openings and out on the floor. Using such a technique, there is a risk that milk remaining far up in the milk tubes to which the teat cups are attached, after washing, flows down into the teat cups and contaminates the same.
Another prior art teat cup cleaning technique is depicted in U.S. Pat. No. 4,061,504 (CORNELL RESEARCH FOUNDATION) and in the Swedish patent application No. 8600770 (TAURINA) and comprises a forward flush method, wherein the cleaning liquid is injected into the teat cups from a cleaning liquid supply tank and flushed through a major part, including the milk jar, of the milking system and back to the cleaning liquid supply tank in a closed loop. Such a cleaning technique is however not intended to be performed such frequently as between the milking of each milking animal.
Still another prior art teat cup cleaning technique is disclosed in EP 0,385,539, A2 (LELY) and EP 0,510,779, A2 (LELY). Here, a rinse fluid container is connected to teat cups in upright positions, via respective rinse lines and rinse jetters, said jetters being attached to the respective teat cups in a fluid-tight manner, whereafter, due to vacuum, rinse fluid is sucked from the container, through the rinse lines and the jetters and into the teat cups, and further through respective milk lines to respective milk meters. Inside the milk meters, the rinse fluid flows from respective milk receptacles to respective measuring chambers, from where it is pumped (in the same manner as milk during milking) through respective discharge lines, and into a common discharge line. At the end of this common discharge line there is provided a three-way valve for feeding the rinse fluid through a second rinse line and back to the rinse fluid container in its first position and for admitting milk to be fed through a further milk line and to a milk jar loop in its second position.
Drawbacks of this cleaning technique includes that there may be a risk of contaminating collected milk in the milk jar loop if the three-way valve fails. The pumping of the rinse fluid through the common discharge line and the three-way valve gives an over-pressure in the three-way valve, the three-way valve thus being the only component that prevents rinse fluid from leaking into the milk jar loop. Further, the fluid-tight attachment of the jetters and the upright positions of the teat cups limit the discharge of all rinse fluid to be performed through the three-way valve.
WO 96/11568 (MAASLAND) discloses still another cleaning technique, which should be acknowledged, this technique being particularly designed for teat cup cleaning between pre-milking and milking. Three-way valves are arranged in immediate vicinity of respective teat cups, said valves connecting to respective pre-milking lines in their first positions and to respective milking lines in their second positions. No details of the washing principle as such are disclosed.
Accordingly, it is an object of the present invention to provide a method for teat selective milking and teat cup selective cleaning in an automated milking system, which avoids at least some of the problems associated with prior art systems.
It is in this respect a particular object of the invention to provide such a method that is effective, fast, accurate, reliable, safe, easy to install and perform, and particularly of low cost.
It is yet a further object of the invention to provide the method, which may be implemented by using a minimum of equipment.
These objects among others are, according to one aspect of the invention, attained by a method as claimed in claim 1.
A further object of the present invention is to provide an apparatus for performing the method according to the first aspect of the invention.
In this respect, it is yet a further object of the invention to be integratable in an automated milking system.
Consequently, there is according to a second aspect of the present invention provided an automated milking system as claimed in claim 17.
Further characteristics of the invention and advantages thereof will be evident from the following detailed description of embodiments of the invention.